Combination gas and electric heater for a clothes drier



Nov. 17, 1964 P. W. DOUGLAS COMBINATION GAS AND ELECTRIC HEATER FOR A CLOTHES DRIER 5 Sheets-Sheet 1 Filed April 5, 1961 INVENTOR DEYTOU LU. [Dour L-ks ATTORNEY Nov. 17, 1964 P. w. DOUGLAS 3,157,390

COMBINATION GAS AND ELECTRIC HEATER FOR A CLOTHES DRIER Filed April 5, 1961 5 Sheets-Sheet 2 I I /7 i- .m. .lwl fi Hm INVENTOR 71 7'. 5 DEYTOUWDOUQLKS ATTORNEY Nov. 17, 1964 P. w. DOUGLAS 3,157,390 COMBINATION GAS AND ELECTRIC HEATER FOR A CLOTHES DRIER Filed April 5, 1961 5 Sheets-Sheet 3 5 1 9 Eleciwl: [YIN 7 Y Mrmosfaf Solenoid 8/ 5a eijy "flier/nos; f 6 2 I J l f h a Hillrmosfb? 99 U 2 96 I 77 97 76 74 j i- 5 INVENTOR DeYTou W Douquxs Timer BY n/174 M ATTORNEY Nov. 17, 1964 P. w. DOUGLAS 3,157,390

COMBINATION GAS AND ELECTRIC HEATER FOR A CLOTHES DRIER Filed April 3, 1961 5 Sheets-Sheet 4 INVENTOR pEYTOHWDOUqLA ATTORNEY Nov. 17, 1964 P. w. DOUGLAS COMBINATION GAS AND ELECTRIC HEATER FOR A CLOTHES DRIER Filed April 5, 1961 5 Sheets-Sheet 5 INVENTOR m M? D M l United States Patent 3,157,391) COMEINATEGN GAS AND ELEQTiEEC HEATER ESTER A QLQTETES DRIER Peyton W. Douglas, Syracuse, N311, assignor to Electrstone Qorporation, a corporation of New York Fiied Apr. 3, wall, Ser. No. 1%,129 3 Ct. 26333) This invention relates to improvements in domestic clothes driers of the rotating drum type. More particularly, the invention is directed to means for heating such driers in a manner to enable their use in the drying of all kinds of apparel and fabrics.

Currently available domestic clothes driers of the rotating drum type are purchased by much of the public because of their convenience and reasonable price. In addition to this, many laundry establishments have been et up where those without washing and drying equipment may, for a consideration, rent the use of such equipment. Thus, with the exception of commercial laundries, the general public has access to and makes considerable use of clothes drying machines. This, of course, suggests that these machines are expected to quickly and safely dry any and all kinds of fabrics that any of the many users desire to launder.

Presently, due to the improved treatment of well known fabrics, as well as development of synthetic materials, it is found that wearing apparel or fabrics cannot be washed and dried under conditions or in time periods common to all such apparel or fabrics. With particular reference to driers, it has become evident that they must be pro vided with heat controls by which to produce several different drying temperatures. This has posed no serious problem when the drying heat is created by an electrical unit operating on a 220 or 230 volt circuit. However, there are many present and potential users of driers to whom such current is not available. A problem, therefore, does exist when only the usual household current is available. This is largely because a heating unit operable on this current either cannot produce'adequate heat to dry certain fabrics, or requires a considerable period of time to accomplish the drying. Some driers, of course, incorporate gas heaters but such heaters are limited to providing a set drying temperature since it has been found impractical to install fool-proof expensive valve controls in devices of this nature that are so generally available to and used by the public.

The present invention has for one of its objects the provision of a drier that incorporates such heater equipment as to enable drying all manner of fabrics in a safe and acceptable time period.

Another object of the invention lies in the provision of a drier having multiple heating units that are operable selectively or in combination for the purpose of producing given drying temperatures.

A further and important object of the invention lies in the provision of a drier in which all of the electrically operable parts, including multiple heating units, function on conventional house current through appropriate controls.

A more particular object of the invention lies in the provision of a heating unit in a drier that takes the form of a combined gas burner and electric heater.

A still further and important object of the invention lies in the provision of a control system for operation of a combined gas and electric heater, the system enabling either or both of the heaters being utilized to produce desired drying temperature for any given kind or type of fabric.

Other objects and advantages of the invention will be more fully understood from a consideration of the following specification, taken in conjunction with the accompanying drawings; in which PEG. 1 is a perspective view of a rotating drum type clothes drier, part of the cabinet being broken away to generally locate the multiple element heating unit embodying the invention;

FIG. 2 is a side elevational View of the drier, parts of the cabinet and drum being broken away to disclose the heating unit and general air circulation within the drier;

FIG. 3 is an enlarged front elevational view of the heating unit and shows the various parts as they would appear from viewing the heater through the rear of the drum;

PEG. 4 is an enlarged rear elevational view of the heating unit;

FIG. 5 is a vertical sectional view of the heating unit, taken substantially as suggested by the line 55 Of FIG. 3; and

FIG. 6 is a wiring diagram showing the arrangement for selectively or combinedly operating and controlling the gas and electric heater elements.

Renerring more particularly to the drawings, the reference numeral 19 is employed to generally designate a clothes drier cabinet in which one form of the invention is embodied. This cabinet may be of sheet material construction and includes a front wall 11, side walls 12 and 1'3, and rear wall 14. The base portion 16 has a toespace setback 17. A top wall or cover 18 closes the upper end of the cabinet and includes a depending marginal flange or rim 1? that is suitably seated on the upper edges of the vertical walls of the cabinet. Suitable air intake louvers 21 are provided adjacent the lower portion of the cabinet rear Wall 14.

The front wall 11 has an opening 22 giving access to the front interior of the cabinet which is presently shown to be framed by a rectangular stepped portion 23. A rectangular door 24, suitably hinged along one vertical edge, is intended to close the entire area defined by the stepped portion 23 as Well as the access opening 22. The space Within the cabinet is divided into two vertical compartments; namely, a large drum receiving compartment 26 and a rear compartment 27. These compartments are formed by a vertically disposed bulkhead 23 which er:- tends the full height of the cabinet. Midway of its sides, the bulkhead Z8 is provided with an opening 29 which, for purposes of operation of the drier shown, is centered with the access opening 22 in the front wall 11.

The large front compartment as encloses a cylindrical tumbling drum 31 which includes a peripheral wall 32 and front and rear rear Walls 33 and 34 respectively. The wall 32 has perforations 36 which are located forwardly of the drum in much the manner and to an extent suggested in FIG. 2 of the drawings. The front and rear walls 33 and of the drum are provided with central openings 37 and 38, respectively. The front opening 317 is appropriately closed by the cabinet door 24, whereas the rear opening 38 gives air access into the drum through the bulkhead opening 29. A suitable hear ing ring 39, framing the circular opening 38 or" the drum rear wall, is supported by a correspondingly arranged ring il. mounted on the bulkhead Similar interiitt'ng bearing rings are provided to mount the forward end of the drum on the cabinet front wall 11. The drum is rotated on these hearings by a motor through a drum belt 43 and motor belt A. belt as, shown in PEG. 1, connects the motor 42 with and drives a suitable suction fan (not shown) that is mounted at the rear end of a trough d7 which defines the'base or bottom of the large front compartment 2s. A drawer type lint trap it; separates the body of the compartment as from the trough 4'7 (see FIG. 2) and enables convenient periodic withdrawal of lint accumu- 349 lated during operation of the drier. Operation of the fan draws air into the rear compartment 2? through the louvered rear wall 14- of the cabinet, thence into the front compartment 26 by way of a heater 51 and drum 31. The air, after passing through the lint trap 43, exits from the cabinet by way of suitable exhaust ports directl associated with a housing for the fan.

The heater 51, located in the rear compartment 27 and embodying one form of the invention, comprises a housing 52 which includes a rear wall 53, top and bottom walls 54 and 56, respectively, and side walls '7. The forward edges of the top, bottom and side walls are outwardly flanged, as at 58, in, a manner to provide a rim to the forward open face of the housing. This rim abuts and is secured to the rear face of the bulkhead and completely surrounds the bulkhead opening 29. The rear wall 53 is provided with one or more openings 59 which permit air within the rear compartment 27 being drawn into the housing 52. An opening or is also made in the bottom wall as directly above the top wall 6% of an air exhaust compartment. One of the side walls 57 has an aperture 62 with which the nozzle 63 of a gas burner 64 is intended to register, substantially as suggested in FIGS. 3 and 4. Spacedly overlying the bottom wall opening at is a horizontally extending bathe plate or. The end of this plate remote from the burner aperture 62 is flanged upwardly, as at at, to provide an end bathe. The purpose of the end battle is to confine the flame of the burner 64 to the interior of the housing and at the same time permit intake of air through louvered vents dd in one of the side walls 57. Adjacent the forward or open face of the housing, a plate as is provided. This plate is attached at its lower edge to the bottom wall 56 and extends upwardly a distance possibly slightly less than hair" the height of the housing This plate is, of course, permanently secured not only to the bottom wall 56, but also along suitable flanges to the side walls 57 and at its upper end continues in an inwardly inclined baflle plate '71. As shown in HQ. 5, the plate 71 serves to mount the elements 72 of an electric heater 73. The plate ill serves as a deflector to prevent damage to the heating elements "22 when the gas burner 64 is operated. Suitable electrical leads 74 and 76 connect the heater 73 with a switch 77 and a timing mechanism, may be in series with either lead 74 or K. timer is not shown inasmuch as it may be of any acceptable form.

Referring more particularly to FIGS. 3 and 4, it will be noted that the gas burner 54 is provided with a gas it is contemplated that the drier in which the present in- I vention is shown may be provided with a drying heat from either the gas burner at or the electric heater '73, or a combination of both, a gas pilot d? is provided,

the jet till thereof being adjacent the burner nozzle The line 519 from the pilot 87 connects with a pilot valve 91. This valve, through a tube 92, is also thermostatically coupled with the pilot 87. To prepare the gas burnor for use, a button 93 is depressed and so held until the thermocouple locksthe. pilot line open, thus enabling lighting the pilot.

Attention is no particularly directed to the wirin diagram of FIG. 6. Herein, electrical leads 7d and it; are shown as coming from a timer mechanism that is operatively connected with a source of conventional household current. .The lead 7 passes through a safety thermostat v94, control thermostat 82'and enters the switch d- 77 at terminal 96. A switch arm 97 is operable to connect the timer lead '74 with an output terminal 98, from which a lead as passes through a control thermostat llilll to heater 73 and returns to the other timer lead '76. in other words, when the switch arm 97 is closed to connect terminals 96 and @8, the electric heater 73 can be energized at such time and to an extent determined by manipulation of the timer from an off to a desired on period. When a drying temperature has been reached, such as the control thermostat Till will break the circuit and thus shut oil the heater 73. Should the control thermostat 2 malfunction, or should the heat in the drier, for any other reason, tend to become excessive, the safety thermostat Wt will automatically function to break the circuit when the drier temperature has reached approximately 170.

Referring now particularly to the circuit involving the gas burner 64, it is to be noted that the switch 77 is provided with another terminal M2. When the switch is operated to connect terminals as and Th2, current passes from timer lead '74 through thermostats dd and 32 and line 81 to solenoid 3d that controls operation of the main shut-01f valve 79. From the solenoi s, a lead MP3 joins the other line '76 to the timer. Assuming that the pilot 8'7 has been lighted, closing the switch 97 as between terminals 96 and 1% will effect opening the main gas valve, and burner 64 will function. Since the sole noid of the gas shut-off valve is in this circuit, it is obvi ous that when the temperature within the drier reaches approximately the limit defined by thermostat 82, this circuit will be broken and the solenoid will shut oil the gas burner However, should any malfunction occur in the timer or the control thermostat 32, the safety thermostat 94 will function at a maximum drier temperature of to break the circuit and cause the solenoid to shut off the supply of gas to the main burner.

As is well known, an electric heater operating on house current does notsatisfactorily eiiect drying of the average type of clothes because of the fact that the output is relatively low and drying time would extend over an excessively long period. However, many synthetic fabrics or a combination of synt ietic fabrics withwool, cotton, or silk cannot be safely dried at anything but a relatively low temperature. Thus, when delicate fabrics, or those subject to damage when exposed to relatively high temperatures, are to be dried, the switch 7'7 is closed to connect terminals 96 and 925 and the control thermostat 1 51 in this circuit will shut 01f the heater 73 at a maximum temperature considered suitable to dry such fabrics even though the timing mechanism may have been set for a period in excess of that required.

As mentioned above, gas burners of the nature usable in a clothes drier are not safely and economically subject to use with a variable supply control, and consequently, a 7 gas burner must either be completely shut off or operatingv to its full capacity. As proposed, the burner 64 may be designed to provide a gas tlame that is either the equal, in

fabrics and, thus, by closing the switch 77 to connect terminals and M2, the gas burner may be used as the sole source of drying heatand will, of course, only function for the period of time for which the timer is set or for a shorter period, should the temperature reach" 140, the

setting of the control thermostat 82.

There are instances when'clo'thes or other fabrics that B.t.u.s, be the equivalent of the total B.t.u.s of both heaters. The electric heater 73 will automatically cut out when the set maximum temperature has been reached in the control thermostat 1G1. Subsequently, when the set maximum temperature of the control thermostat 82 has been reached, the gas burner 64 will be shut off and the clothes or fabrics subjected to the combined heat of these units will be found to have dried in a considerably lesser period of time.

Although applicant has shown and described only one form of a combined gas and electric heater for a rotating drum type clothes drier, it will be understood that structural variations may be made and are contemplated in the use of the invention with other types of driers insofar as such variations are encompassed by the annexed claims.

Having thus set forth my invention, what I claim as new and for which I desire protection by Letters Patent is:

1. In a clothes drier having a cabinet and a bulkhead vertically dividing the interior thereof into a front rotatable drum compartment and a rear heater compartment, an air heating unit in said rear compartment ernbracing an opening in said bulkhead leading into said front compartment, said unit comprising an enclosure having inlet ports, an electric heater in the upper portion of said enclosure, a gas burner in the lower portion of said enclosure, means in said unit for deflecting heat from said burner around said heater and through said bulkhead opening into said front compartment, manually controlled means connecting said burner and said heater with their respective sources of supply, said means including gas supply means having a solenoid valve and circuitry operating said solenoid valve and said heater, said circuitry including switch means connected with an electrical current supply and operable to selectively and combinedly activate said solenoid valve and said heater, and automatically operated temperature responsive means associated with said burner and said heater for individually terminating their operation when a predetermined temperature has been reached in said front compartment.

2. In a clothes drier having a cabinet and a bulkhead vertically dividing the interior thereof into a front r0- tatable drum compartment and a rear heater compartment, an air heating unit in said rear compartment embracing an opening in said bulkhead leading into said front compartment, said unit consisting of an enclosure containing a gas burner and an electric heater in superposed relation, gas supply means including a solenoid valve for operating said gas burner, circuitry connected with said gas burner operating solenoid valve and said heater, said circuitry including switch means, connected with a single current supply, operable to selectively and combinedly activate said solenoid valve and said heater, baffle means in said enclosure above said burner operable to defiect heat from said burner around said electric heater and through the opening in said bulkhead, means for circulating air through said unit and said drum compartment and control thermostats in said circuitry for opening the circuits of said solenoid and said heater when a predetermined temperature has been reached in said drier.

3. In a clothes drier having a cabinet and a bulkhead vertically dividing the interior thereof into a front rotatable drum compartment and a rear heater compartment, an air heating unit in said rear compartment embracing an opening in said bulkhead leading into said front compartment, said unit consisting of a gas burner and an adjacent electric heater, baflie means between the burner and heater deflecting heat from the burner around said electric heater and into said opening in the bulkhead, gas supply means including a solenoid valve connected with said burner, electrical circuitry connected with said solenoid valve and said heater, said circuitry including multiple position switch means connected with a single current supply operable in one position to energize the electric heater to provide low heating, in a second position to energize the solenoid in the gas supply means to energize the burner and in a third position to energize both the electric heater and the solenoid to provide a combination of heat from both sources, means for circulating air through said unit and said drum compartment and control thermostats in said electrical circuitry for opening the circuits of said heater and said solenoid when a predetermined temperature has been reached in said drier.

References Cited in the file of this patent UNITED STATES PATENTS 1,459,049 De Khotinsky June 19, 1923 2,063,896 Martin Dec. 15, 1936 2,242,630 Steingruber May 20, 1941 2,756,321 Pappas July 24, 1956 2,798,307 Reiter July 9, 1957 2,820,623 Soffer Jan. 21, 1958 2,893,639 Martin July 7, 1959 

1. IN A CLOTHES DRIER HAVING A CABINET AND A BULKHEAD VERTICALLY DIVIDING THE INTERIOR THEREOF INTO A FRONT ROTATABLE DRUM COMPARTMENT AND A REAR HEATER COMPARTMENT, AN AIR HEATING UNIT IN SAID REAR COMPARTMENT EMBRACING AN OPENING IN SAID BULKHEAD LEADING INTO SAID FRONT COMPARTMENT, SAID UNIT COMPRISING AN ENCLOSURE HAVING INLET PORTS, AN ELECTRIC HEATER IN THE UPPER PORTION OF SAID ENCLOSURE, A GAS BURNER IN THE LOWER PORTION OF SAID ENCLOSURE, MEANS IN SAID UNIT FOR DEFLECTING HEAT FROM SAID BURNER AROUND SAID HEATER AND THROUGH SAID BULKHEAD OPENING INTO SAID FRONT COMPARTMENT, MANUALLY CONTROLLED MEANS CONNECTING SAID BURNER AND SAID HEATER WITH THEIR RESPECTIVE SOURCES OF SUPPLY, SAID MEANS IN- 